Aussies Corporal Seamus Donaghue and Private Heath Jamieson, both wounded in combat in Afghanistan, are taking part in the 335km-journey to the South Pole, along with wounded soldiers from the UK, US and Canada.

Prince Harry is joining the UK team on the gruelling journey, during which temperatures are forecast to drop to minus 40C.

Mr Abbott says the two Aussie soldiers are embarking on an "extraordinary journey".